Window structure

ABSTRACT

A window structure comprising a rectangular window frame, a rectangular sash frame within the window frame and supporting a glass pane, pivotal mounting means at and between the tops and bottoms of the frames on the central vertical axes thereof and comprising pivot pin plates mounted on the sash frame and having vertical pivot pins projecting therefrom and receiver fixtures mounted on the window frame and having bearing openings rotatably receiving the pivot pins, one of said mounting means including stop means to stop pivotal opening of the sash frame when that frame is pivoted to a predetermined partially opened position and comprising a key plate shiftably carried by the receiver fixture and normally occurring radially outward of the pin, spring means urging the key plate toward the pin, a keyway in the pin and shiftable into alignment with the key plate when the frames are moved to said partially open position, whereupon the plate shifts into stopping relationship in the keyway and manually operable operating means to yieldingly urge the key plate out of the keyway.

United States Patent i 1 Walter l l WINDOW STRUCTURE Edward M. Walter, 323- l/4 W. Francisco St, Carson Calif 90745 22 Filed: Jan. 13, 1975 21 Appl. No.: 540,677

[76] Inventor:

Primary lzlraminer-Kenneth Downey Attorney, Agent or Firm Georges A, Maxwell [5 7] ABSTRACT A window structure comprising a rectangular window Oct. 14, 1975 frame, a rectangular sash frame within the window frame and supporting a glass pane, pivotal mounting means at and between the tops and bottoms of the frames on the central vertical axes thereof and comprising pivot pin plates mounted on the sash frame and having vertical pivot pins projecting therefrom and receiver fixtures mounted on the window frame and hav ing bearing openings rotatably receiving the pivot pins one of said mounting means including stop means to stop pivotal opening of the sash frame when that frame is pivoted to a predetermined partially opened position and comprising a key plate shiftahly carried by the receiver fixture and normally occurring radially outward of the pin, spring means urging the key plate toward the pin, a keyway in the pin and shift-able into alignment with the key plate when the frames are moved to said partially open position. whereupon the plate shifts into stopping relationship in the keyway and manually operable operating means to yieldingly urge the key plate out of the keyway.

l0 Claims, I] Drawing Figures US. Patent 0a. 14, 1975 Sheet 1 of2 3,911,623

WINDOW STRUCTURE This invention has to do with an improved window structure and is more particularly concerned with improved hardware for and in combination with rotatably mounting window sash and frame structures.

In the building art and particularly in the art of industrial and commercial buildings, where the provision of large or extensive window openings provided with appropriate frame and sash is common place, it has long been accepted practice to fix such sash in their related frames. That is, to established fixed windows that are incapable of being opened.

It has been recently determined that fixed window structures, such as referred to above, in a great many instances, are not satisfactory and are in fact undesirable. The most common instance where fixed window structures have been found wanting is in window openings in multi-story commercial buildings, particularly in window openings above the ground floor of such buildmgs.

The objections to fixed windows in such circumstances resides in the fact that their exteriors must be cleaned at the exterior of the buildings, they prevent ingress and egress in the event of emergencies and they afford no ventilation. in addition to the above noted basic shortcomings, fixed window structures, such as provided by the prior art, are wanting in a number of other less apparent respects; for example, the sash being fixed in their related frames make servicing and- /or replacement of the sash, as when the glass panes thereof are broken, difficult, time consuming and costly.

in recent years, in order to overcome the basic shortcomings to be found in fixed window structures of the type or class noted above, the art has developed and resorted to movable window structures wherein the sash are pivotally mounted in their related frames on the central vertical axes of the sash, whereby the sash can be rotated in their frames to dispose the outsides thereof, inwardly, for the purpose of cleaning their glass panes. Such pivotally or rotatably supported sash also makes possible the establishment of substantially free ingress and egress through the window openings in cases of emergency and can, in the event of an emergency, such as when air conditioning equipment is rendered inoperative, as a result of power failure, or the like, establish or provide for ventilation.

The pivotally or rotatably supported sash provided by the prior art distinguishes over fixed window structures by the provision of special hardware characterized by socket fixtures fixed centrally of the top and bottom portions of the window frames and pivot pin fixture plates fixed centrally of the top and bottom portions of the window sash with the pivot pins thereof engaged in the sockets of their related fixtures. The above noted sash are normally fixed within their related frames, on common planes therewith and are normally sealed in and with the frames by suitable sealing means about the interior of the frames and about the outer perimeters of the sash. The sash are normally releasably secured in normal, closed positions in the frames by suitable, manually operable bolt or latch-type locking means or devices engageable at the interior of the window structures, carried by the frames, at one side thereof and engageable with the adjacent sides of their related sash.

With the special means or hardware described above, it will be apparent that the sash, upon release of the locking means are free to be rotated within their frames, to afford cleaning of the window panes and afford emergency access and/or ventilation through the window openings.

While the above noted, advanced state of the art has overcome certain shortcomings found in fixed window structures, it has proven to be wanting as regards the establishment of ventilation through windows in a controlled and on-going manner when and where such ventilation is deemed necessary and/or desirable.

In the interest of health and safety, as well as in the interest of the conservation of energy, it has been determined and is now being required that in the case of rotatably or pivotally mounted window and slash structures of the character referred to above, means must be provided to enable opening and releasably securing the sash in a predetermined, partially opened position, to afford a predetermined amount of ventilation therethrough, so that air conditioning equipment can be put out of service when circumstances permit, to conserve energy and so adequate ventilation can be established through such window structures in the event of break down or malfunctioning of such air conditioning equipment.

In carrying out the above, due consideration must be and has been given to the safety of persons working on and about such windows and requires that the windows do not open to such an extent that persons might fall through the openings and/or that the sash will not be moved by air currents or the like with potential adverse effects.

To the above end, the prior art has proposed and, to a limited extent, employed special strut or link-type manually operable, releasable latches fixed to and extending between related sides of the window frames and sash, which can be employed to secure the sash in a predetermined partially opened condition, for ventilation. Such means while effective, are unsightly, inconvenient and awkward to use and have been found to be too easily tampered with by unauthorized persons and therefore potentially dangerous or unreliable.

It has developed that in those instances where means must be provided to releasably maintain window structures of the character here referred to in a partially open ventilating position, that the sash be held open at an angle of 15 to 20 from its normal closed plane or position.

It is to be particularly noted that the frame, sash and hardware structure of the type or class here concerned with have become substantially standardized. The frames are characteristically simple rectangular frames established of elongate right angularly related and secured, metal sections. The upper and lower sections are commonly rectangular C-sections, the longitudinal openings of which are disposed inwardly and are approximately l-A inch wide to accommodate standard weather sealing means or strip and provide access to the interior of the sections and accommodate those means employed to secure the frames in their related window openings and are approximately 1- /4 inch deep to accommodate said fastening means. The sash, framing the glass frames are simple rectangular frames established of right angularly related, substantially square sections with means at their inner sides to receive and retain the glass and normally characterized by an outwardly opening channel about l-/4 inch wide and oneeighth inch to one-fourth inch deep to cooperate with and/or receive and carry strips or elements of the weather sealing means provided. The sash are dimensionally smaller than the frames to permit free disposition and relative pivotal movement of the sash within the frames.

As a result of the above substantial standardizing, the above noted socket fixtures and pivot pin plates provided to pivotally mount such sash in such frames have become substantially dimensionally standardized. That is, the socket fixtures are no wider than the inside slots of and are no higher than the depth of the frame sections so that they can be advantageously received in and fixed with or to their related frame sections and the pivot pin plates are such that they can be and are substantially disposed within the confines of the outside channels of the sash when fixed thereto.

The above noted standardizing of frames, sash and hardware is not invariable, but has become sufficiently uniform that it can and will be considered as standard for the purpose of disclosing the instant invention.

An object and feature of my invention is to provide an improved frame and sash window structure wherein the sash is pivotally mounted in the frame on its central vertical axis by pivotal mounting means at and between the related frame and sash section at the top and bottom of the structure and which includes novel stop means to releasably maintain the sash in a predetermined partially opened position relative to the frame.

It is another object and feature of my invention to provide a structure of the character referred to above wherein the stop means is automatically engageable when the sash is pivotally moved from its normal closed position toward an open position and which is manually releasably to effect pivoting the sash to a fully open position or back to its normal closed position.

Still another object and feature of my invention is to provide a structure of the character referred to wherein said stop means is incorporated in one of the related socket fixtures and pivot pin plates of the pivotal mounting means for the sash.

It is yet another object and feature of my invention to provide an automatically engageable and manually releasable stop means in the pivotal mounting means for a sash, as set forth above, which means does not dimensionally alter the mounting means or otherwise render it incompatible with standard frame and sash structures.

Finally, it is an object and feature of the instant invention to provide a stop means of the character referred to which can be rendered substantially tamperproof.

The foregoing and other objects and features of the invention will be understood and will be apparent from the following detailed description of a preferred form and carrying out of the invention, throughout which description reference is made to the accompanying drawings in which:

FIG. I is an isometric view of a window structure embodying the invention, in a closed position.

FIG. 2 is a view similar to FIG. 1 showing the window structure in a partially opened, stopped position.

FIG. 3 is an enlarged sectional view taken as indicated by line 3-3 on FIG. 1;

FIG. 4 is an enlarged sectional view taken as indicated by line 4-4 on FIG. 1;

FIG. 5 is a view taken as indicated by line 5 5 on FIG. 4;

FIGS. 6 and 7 are enlarged sectional views taken as indicated by lines 6-41 and 77 on FIG. 1,

5 FIG. 8 is an enlarged detailed sectional view taken as indicated by line 8-8 on FIG. 5'.

FIG. 9 is a sectional view taken as indicated by line 9-9 on FIG. 8;

FIG. 10 is a view similar to a portion of the structure illustrated on FIG. 8 and showing parts in another posi tion', and

FIG. I] is a view similar to FIG. 9 showing parts in another position.

Referring to FIGS. 1 and 2 of the drawing, the basic window structure A includes a window frame F in an opening (not shown) in a wall W, a sash frame 5 and a glass pane G arranged within and supported by the frame F.

The frame F is a substantially rigid, integrated. rectangular, framework having horizontal top and bottom sections 10 and l! (header and sill) and vertical side sections 12 (stiles). The frame can be secured in the opening in any desired and suitable manner (not shown). Referring to FIGS. 1 through 4, 6 and 7, the top and bottom sections 10 and II can, for example. be formed of extended alluminum, substantially rectangular C-sections and are characterized by substantially flat, inwardly disposed inside walls 14 with central longitudinal access slots I5 (about I-% inch wide) and flat outside or bottom walls 16 spaced outwardly from the wall 14 (about IVi inch).

the walls I6 provide structure for securing the frame into a related window opening by means of screw fasteners or the like, and a mounting structure for pivotal mounting means M and M' for the sash S.

The slots in the inside walls 14 provide access to the interiors of the sections 10 and II and to the fastening means for mounting the frame. They further accommodate and provide access for the mounting means M and M and means to receive and support suitable weather sealing means (not shown).

Apart from the above, the frame F can vary widely in form and construction without in any way affecting the novelty of the instant invention. Accordingly, further detailed illustration and/or description of the frame F is not necessary for the purpose of disclosing the instant invention and will not be entered into (so as not to unduly burden this disclosure).

The sash or sash frame S is a substantially rigid, integrated, rectangular framework about or in which the glass pane G is mounted and supported and is characterized by horizontal top and bottom sections or members 20 and 21 and vertical side members 22. The sash S is slightly smaller in outside dimensions than the inside dimensions of the frame F whereby the sash can be freely arranged within the frame, as shown, and in ac cordance with common practice.

In the preferred carrying out of the invention and as shown in FIGS. 3, 4, 6 and 7 of the drawings, the top and bottom members 20 and 21 of the sash S have flat inwardly disposed surfaces 23 which normally occur in spaced opposing relationship with the inside walls of the top and bottom sections 10 and 11 of the frame F and which can, as shown, be provided with longitudi nally extending, inwardly opening, channels 24 to receive elements or portions of the weather sealing means (not shown) and in which parts of the pivotal mounting means M and M can be conveniently mounted.

Apart from the above noted specific details the sash can very widely in form and construction without affecting the novelty of this invention. Accordingly, fur ther detailed consideration of the sash structure can and will be dispensed with.

The pivotal mounting means M and M for the sash S occur in vertical spaced relationship on the central vertical axes of the frame F and sash, the means M occurring on and between the bottom section and member ofthe frame and sash and the means M occurring on and between the top section 21 and member 11 of the frame and sash.

The means M' at the top ofthe window structure and shown in FIG. 3 of the drawings includes a lower pivot pin plate P and an upper socket or receiver fixture R'. The plate P includes an elongate, flat, base plate with fastener receiving openings 31' in its opposite end portions and has a central upwardly projecting pivot pin 32'. The plate 30' is preferably provided with an annular boss about the pin defining a fiat upwardly disposed bearing surface 33'. The plate preferably corresponds in general cross-sectional dimensions with the channel 24 in the sash member 20, is seated in the channel, is fixed therein and with the member 20 by suitable screw fasteners 34' so the pin 32 projects freely upwardly from the sash frame S, on the central vertical axes thereof, substantially as shown.

The socket or receiver fixture R includes an elongate, flat base plate 40' with fastener receiving open ings 41' in its opposite end portions and has a central downwardly projecting annular boss 42' defining a central, elongate, downwardly opening pin receiving socket or bearing opening 43 and an annular, downwardly disposed bearing surface 46.

The socket fixture R is fixed to and carried by the top section [0 of the frame F with its boss 42 and socket opening 43' on the central vertical axis of the window structure and opening downwardly to be rotat ably engaged with or receiving the pin 32' of the plate P. Finally, the means M is provided with a suitable annular spacer and anti-friction washer 48, about the pin and between the bearing surfaces 33' and 47'.

In practice, and in the preferred carrying out of the invention, the fixture corresponds generally in lateral extent with the slot 15 in the top section 10 of the frame, corresponds generally in vertical extent with the inside vertical extent of the section It) and is arranged in the section 10 with its base secured to the (top) outside wall 16 of the section 10 by screw fasteners 44' and with the lower end of the boss 42' terminating substantially within the slot 15, as shown in FIG. 3 of the drawings.

In practice, and as shown, the boss 42' has a removable section 45 to provide lateral access to the opening 43 and to thereby facilitate assembly of the window structure, when the plate P and fixture R are fixed to the frame and sash and the sash is moved into and out of cooperative, mounted engagement in the frame. The section 45' occurs at a side of the boss disposed along the longitudinal axis ofthe base 40 and is normally releasably secured in place in the boss and with the plate by a screw fastener 46. substantially as shown.

Finally, the top of the boss 41 defines a fiat annular bearing surface 47' to oppose the bearing surface 33 of the plate P.

The pivotal mounting means M illustrated and described above is old in the art and is a substantially standardized pivotal mounting means or structure for window structures of the character here concerned with.

In accordance with the teaching of the prior art. two like mounting means such as the means M are provided to mount a sash within a frame, one such means being at and between the top of the frame and sash. as shown in FIG. 3 and another like means being at and between the bottom of the sash and frame.

In the instant invention, the mounting means M at and between the bottom of the sash S and frame F is similar to the means M at the top of the sash and frame and described above, and is further provided with and /or includes novel stop means N, as will hereafter be described.

The means M includes a pivot pin plate P with a base 30, opening 31, pin 32 and bearing surface 33, similar to the base 30'. opening 31', pin 32' and surface 33' of the pivot pin plate P. The plate P is related to the channel 24 in the bottom member 21 of the sash S and is sc cured thereto by fasteners 34 in the same manner in which the plate P is related and fixed to the sash section 20 and as clearly shown in FIGS. 4, 6 and 7 of the drawings.

The single significant difference between the plates P and P resides in the fact that the pin 32 of the plate P is provided with a longitudinally extending, radially outwardly opening key slot X (sec FIGS. 8 through ll of the drawings).

The socket or receiver fixture R of the means M is similar to the fixture R of the means M in all respects except for its vertical disposition and for the novel stop means N which it includes.

As will be apparent from and examination of the drawings, the fixture R includes a base 40 with openings 41, bars 42, opening 43, related fasteners 44, sections 45, related fasteners 46, surface 47 and related washer 48, corresponding with the base 40', openings 41', boss 42, opening 43', fasteners 44', sections 45', fasteners 46, surface 47 and washer 48' of and/or related to the fixture R of the means M.

The normal cooperative relationship of and between the plate P and fixture R is the same the relationship of and between the plate P and fixture R described above.

In accordance with the above, but for the stop means N, which will be sepecifically described in the following, reference to the foregoing description ofthe means M is to be made as regards the basic structure and relationship of the plate P and fixture R of the means M.

The stop means N incorporated in the pivotal mounting means M, in addition to the previously noted keyway X in the pin 32 of the plate P includes a pivotally supported, spring loaded key plate Y carried by the fixture R and shiftable into and out of engagement in the keyway X in the pin 32.

The key plate Y is a flat unit or part arranged on the central, vertical longitudinal plane of the fixture and is slidably engaged in a vertical slot 50 in the boss 42.

The boss 42 has a primary portion which defines the bearing opening 43 and has an extension 42 extending longitudinally of the base 40 toward one end thereof and to accommodate parts of the means N. The slot 50 is established in the boss and its extension and has an inner end communicating with the bearing opening 43,

an open top and an open outer or rear end, as shown. The key plate Y arranged in the slot 50, is carried by a longitudinal, laterally extending shaft 51 in rotary driving engagement therewith. The shaft is hearing sup ported in registery openings 52 in the boss 42 at opposite sides of the slot 50 and in predetermined longitudi nal spaced relationship from the bearing opening 43 and in predetermined vertical spaced relationship between the upper and lower limits of the slot 50.

The key plate Y is an elongate. flat, vertically disposed plate like part or unit arranged in the slot 50 and is characterized by a substantially straight vertical inner edge 53 which normally occur at and parallel with the open inner end of the slot 50 and normally slidably engages the exterior of the pin 32 of the plate 50, on a vertical line spaced circumfcrentially of the keyway X in the pin The plate is next characterized by a straight. normally horizontal, upper edge 54 converging with the edge 53 to define an upper inner corner portion Z, Spaced rearward of the edge 53 and below the edge 54, the plate is provided with a semi-circular, downwardly and opening, transverse shaft embracing opening 55 with a radially inwardly projecting key lug 56 in its upper portion, The shaft 51 extends through the opening 55 and is provided with a keyway 57 in which the lug S6 ofthe plate is engaged, whereby the plate is carried on the shaft 51 and is keyed therewith in rotary driving relationship,

Finally, the plate Y is provided with a longitudinally outwardly projecting arm 58 at its upper outer portion, which arm projects freely longitudinally outwardly in the slot 50 to intersect the upper portion of a vertical spring bore 60 in the boss, located longitudinally outward of the bearing opening 43, shaft 51 and principal body portion of the plate Y. Arm 58 is engaged by the upper end of elongate, vertical, helical compression spring 61 arranged in the bore 60 and bearing against and between the arm 56 and the bottom of the bore, defined by the base 40 of the fixture.

The spring normally yieldingly urges the arm 56 upwardly and the upper inner corner portion Z of the plate longitudinally inwardly and downwardly toward the pin 32 ofthe plate P, occurring in the bearing opening 43 of the fixture R.

The shaft 51 is releasably retained in engagement in the boss by C-ring means 65 at its opposite end portions, as shown in the drawing.

In the preferred carrying out of the invention and as shown in the drawings, the shaft 51 is provided with an axially extending coupling post 70 at one end, to project laterally and substantially freely from the boss 42 of the fixture and to facilitate coupling the shaft 51 with a suitable manually engageable operating device 71.

ln practice, the post 70 can be a threaded post, or can be a polygonal post, as desired, or as circumstances require, The operating device 71 is in the nature of a lever or key and is characterized by an elongate stem 72 with a threaded or polygonal socket in its inner end to engage the post 70 and has a manually engageable head, or lever arm 73 at its outer end,

In practice, and as shown in the drawings, the post 70 projects toward the inside of the window frame and terminates within the frame section ll. The stem 72 ofthe operating device is engageable through an opening 74 in the inside ofthe frame section ll, in alignment with the post 70 and is rcleasably engaged with the post to establish driving engagement between the shaft 51 and the manually engageahlc portion of the device 71, such as the lever arm 73 illustrated (which remains accessible at the exterior of the frame section 11),

When the sash is in its normal closed position in the frame. the keyway X is out of register or alignment with the key plate Y (See H65. 8 and 9 of the drawings). The keyway X is established in the pin 32 in circumferential spaced relationship from the vertical plane of the key plate the number of degrees from the plane in which the sash occurs when in its closed position to the plane in which the sash occurs when it is pivoted to its predetermined, stopped, partially open position, Accordingly, when the sash is pivoted open and reaches its predetermined partially open position, the keyway X is moved into register and alignment with the key plate Y. Upon rcgistery of the keyway and plate, the upper, inner corner portion of the plate, under the pressure applied onto the plate by the spring 61 is yieldingly urged and moved, or is pivoted, inwardly into keyed engagement in the keyway to stop the sash in said partially open position, The above operation of the means N is effected automatically, without any special or external forces applied directly thereto,

When it is desired to close the window or to open it further, the operating device 71 related to the shaft 51 and accessible at the exterior of the window frame is manually engaged and torsional forces, counter to the force exerted by the spring 61 is applied to the shaft to urge the plate Y to its normal position, whereupon the sash is free to be pivoted back to its closed position or to a further open position and the keyway and key plate are moved out of register with each other.

Finally, and in accordance with common practice, the window structure W is provided with a suitable manually operable latch means 80, at one side of the frame F to releasably latch the sash in its normal closed position, Since such a latch means is standard, or con ventional and its details of construction as well as its specific location can vary widely without affecting the novelty of the present invention, I will not burden this disclosure with further detailed description of the latch means 80.

With the invention described above, it will be appar ent that the window structure can be easily, effectively and dependably moved to and releasably stopped at a partially open position and that this capability is af forded by the simple, inexpensive to establish and dc pendable stop means N that l have incorporated in what is otherwise considered, standard hardware for pivotally mounting windows of the class here con eerned with.

The only modification or alteration of a standard frame and sash with which the instant invention is combined, is the provision of the opening in the frame section ll, to accommodate the operating device 7] for effecting release of the stop means N.

Having described only one preferred form and carry ing out of my invention, I do not wish to be limited to the specific details herein set forth. but wish to reserve to myself any modifications or variations which might occur to those skilled in the art and fall within the scope of the following claims:

Having described my invention, I claim:

I. A window structure comprising a rectangular window frame with horizontal top and bottom sections and vertical side sections, a rectangular sash frame with horizontal top and bottom members and vertical side members freely engagcable within the window frame and supporting a glass pane. said sash frame and pane normally occurring in a closed position wherein said sash and window frames are in a common vertical plane. upper and lower. pivotal mounting means at and between the top section and member and between the bottom section and member of the window and sash frames on the central vertical axes of said frames. said mounting means comprising pivot pin plates mounted on their related sash frame members and having vertical pivot pins projecting therefrom and outwardly from the sash frame and receiver fixtures mounted on their related window frame sections and having a boss with a bearing opening rotatably receiving the pivot pin of the related pivot pin plate. one of said mounting means including stop means to stop pivotal opening of the sash frame relative to the window frame when the sash frame is pivoted to a predetermined partially opened position and the plane of the sash frame is angularly related to the plane of the window frame a predetermined number of degrees. said stop means comprising a key plate shiftably carried by the boss on a plane parallel with the axis of the pin and normally occurring radially outward of the pin. spring means normally yieldingly urging the key plate toward the pin, a longitudinal radially outwardly opening keyway in the pin normally on a radial plane angularly related to the plane of the keyplate equal to the angular relationship of the frames when in said partially open position and shiftable into alignment with the key plate when the frames are moved to said partially open position, whereupon the plate is urged by the spring means inwardly into stopping relationship in the keyway in the pin and manually operable operating means to yieldingly urge the key plate outward relative to the keyway and against the force of said spring means and manually operable latch means between the frames. spaced from the mounting means to releasably hold the frames in their normal, closed position.

2. A window structure as set forth in claim I wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged.

3. A window structure as set forth in claim 2 including pivot means mounting the key plate in the slot on an axis spaced radially outward of the pin and normal to the plane ofthe key-plate. said keyplate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means.

4. A window structure as set forth in claim 3 wherein said spring means biased to rotate the plate in the slot about the axis of the pivot means to urge the keyway engaging portion vertically and radially inwardly relative to the axis of the pin.

5. A window structure as set forth in claim 3 wherein said spring means includes a spring engaging a portion of the keyplatc at a point spaced radially from the axis of the mounting means.

6. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged. pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane ofthe key-plate. said key-plate having a radially and axially extending keyway engaging portion adjaccnt the pin and spaced radially and vertically from the pivot means.

7. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged. pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane ofthe key-plate. said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means. said spring means biased to rotate the plate in the slot about the axis of the pivot means to urge the keyway engaging portion vertically and radially inwardly relative to the axis of the pin.

8. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged. pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the key-plate. said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means. said spring means biased to rotate the plate in the slot about the axis of the pivot means to urge the keyway engaging portion vertically and radi ally inwardly relative to the axis of the pin. and including a spring engaging a portion of the key-plate at a point spaced radially from the axis of the mounting means.

9. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially ex tending slot in which said plate is slidably engaged. pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the key-plate, said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means. said pivot means including an aligned bearing opening in the boss at opposite sides of the slot. and an axial shaft carried by the key-plate projecting into and rotatably engaged in the openings. said operating means including a drive part fixed to and extending axially from one end of the shaft and having a manually engageable member spaced from the fixture.

10. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged. pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the keyplate. said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means, said pivot means including an aligned bearing opening in the boss at opposite sides of the slot, and an axial shaft carried by the key-plate projecting into and rotatably engaged in the openings. said operating means including a drive part fixed to and ex tending axially from one end of the shaft and having a manually engageablc member spaced from the fixture. said spring means including a compression spring car ried by the bars and in the slot radially outward of the pivot means and normally yieldingly engaging portion of the key-plate adjacent thereto to urge the radial outer portion of the plate upwardly and securing the keyway engaging portion radially inwardly and down wardly. 

1. A window structure comprising a rectangular window frame with horizontal top and bottom sections and vertical side sections, a rectangular sash frame with horizontal top and bottom members and vertical side members freely engageable within the window frame and supporting a glass pane, said sash frame and pane normally occurring in a closed position wherein said sash and window frames are in a common vertical plane, upper and lower, pivotal mounting means at and between the top section and member and between the bottom section and member of the window and sash frames on the central vertical axes of said frames, said mounting means comprising pivot pin plates mounted on their related sash frame members and having vertical pivot pins projecting therefrom and outwardly from the sash frame and receiver fixtures mounted on their related window frame sections and having a boss with a bearing opening rotatably receiving the pivot pin of the related pivot pin plate, one of said mounting means including stop means to stop pivotal opening of the sash frame relative to the window frame when the sash frame is pivoted to a predetermined partially opened position and the plane of the sash frame is angularly related to the plane of the window frame a predetermined number of degrees, said stop means comprising a key plate shiftably carried by the boss on a plane parallel with the axis of the pin and normally occurring radially outward of the pin, spring means normally yieldingly urging the key plate toward the pin, a longitudinal radially outwardly opening keyway in the pin normally on a radial plane angularly related to the plane of the key-plate equal to the angular relationship of the frames when in said partially open position and shiftable into alignment with the key plate when the frames are moved to said partially open position, whereupon the plate is urged by the spring means inwardly into stopping relationship in the keyway in the pin and manually operable operating means to yieldingly urge the key plate outward relative to the keyway and against the force of said spring means and manually operable latch means between the frames, spaced from the mounting means to releasably hold the frames in their normal, closed position.
 2. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged.
 3. A window structure as set forth in claim 2 including pivot means mounting the key plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the key-plate, said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means.
 4. A window structure as set forth in claim 3 wherein said spring means biased to rotate the plate in the slot about the axis of the pivot means to urge the keyway engaging portion vertically and radially inwardly relative to thE axis of the pin.
 5. A window structure as set forth in claim 3 wherein said spring means includes a spring engaging a portion of the key-plate at a point spaced radially from the axis of the mounting means.
 6. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged, pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the key-plate, said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means.
 7. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged, pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the key-plate, said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means, said spring means biased to rotate the plate in the slot about the axis of the pivot means to urge the keyway engaging portion vertically and radially inwardly relative to the axis of the pin.
 8. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged, pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the key-plate, said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means, said spring means biased to rotate the plate in the slot about the axis of the pivot means to urge the keyway engaging portion vertically and radially inwardly relative to the axis of the pin, and including a spring engaging a portion of the key-plate at a point spaced radially from the axis of the mounting means.
 9. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged, pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the key-plate, said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means, said pivot means including an aligned bearing opening in the boss at opposite sides of the slot, and an axial shaft carried by the key-plate projecting into and rotatably engaged in the openings, said operating means including a drive part fixed to and extending axially from one end of the shaft and having a manually engageable member spaced from the fixture.
 10. A window structure as set forth in claim 1 wherein said plate is a flat part and said bars define a radially extending slot in which said plate is slidably engaged, pivot means mounting the key-plate in the slot on an axis spaced radially outward of the pin and normal to the plane of the key-plate, said key-plate having a radially and axially extending keyway engaging portion adjacent the pin and spaced radially and vertically from the pivot means, said pivot means including an aligned bearing opening in the boss at opposite sides of the slot, and an axial shaft carried by the key-plate projecting into and rotatably engaged in the openings, said operating means including a drive part fixed to and extending axially from one end of the shaft and having a manually engageable member spaced from the fixture, said spring means including a compression spring carried by the bars and in the slot radially outward of the pivot means and normally yieldingly engaging portion of the key-plate adjacent thereto to urge the radial outer portion of the plate upwardly and securing the keyway engaging portion radially inwardly and dOwnwardly. 